When installing a sub into a sealed box, is it going to be perfectly sealed, or will some air still escape?

The reason I ask is i just put a perfect 10 into a Q-logic box I bought on ebay, well i followed the instructions to a T, however when I push the woofer in with my hand i can hear air creeping out the side of where it's mounted a little bit.

Is this bad? I used the provided foam liner thingies...

 

I dont think that should affect performance of the speaker and no its not bad! now if the speaker is not flush with the box..now you have a problem!

 

I'm pretty sure it's flush as far as I can tell. The problem with the Q-logic boxes is they use that retarded Q-ring design.

If it's not good will I be able to tell right away?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keeks707 &raquo;</TD></TR><TR><TD CLASS="quote">I dont think that should affect performance of the speaker and no its not bad! now if the speaker is not flush with the box..now you have a problem!</TD></TR></TABLE>Yes it is a problem. <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GetawayInMoscow &raquo;</TD></TR><TR><TD CLASS="quote">When installing a sub into a sealed box, is it going to be perfectly sealed, or will some air still escape?

The reason I ask is i just put a perfect 10 into a Q-logic box I bought on ebay, well i followed the instructions to a T, however when I push the woofer in with my hand i can hear air creeping out the side of where it's mounted a little bit.

Is this bad? I used the provided foam liner thingies...</TD></TR></TABLE> Yes it is bad, any air "leaking" out of a sub box is bad, it effects a number of things.
Q logic boxes are, IMO, crap.

If it is a carpeted box, did you cut away the carpet under the subs mounting lip?
Carpet makes a lousy gasket.

There are things you can do to improve the performance of the Q logic box, starting with sealing the MDF the box is made with, [I "paint" the inside of all sub boxes with fiberglass resin, run a bead of silicone along all inside seams, solder the speaker lead to the speaker terminal cup, [inside] then fill it up with silicone, [cover it completely] cut the carpet away from under the subs mounting "lip", if the "foam liner thingies" is not a one piece gasket, make your own. 94

 

there was a post a while back on the elite car audio board where someone put a bead of a moldable clay-like substance that you'd find at a store for artists between speaker and box to form an air-tight seal between box and speaker. This is definetly going to the extreme but I suppose it can't hurt and it's dirt-cheap and won't screw up the lip of your speaker if you need to pull it out.

I'd also tighten the screws on the sub as you would the lug nuts on a wheel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">Q logic boxes are, IMO, crap.</TD></TR></TABLE>

Are you talking about this kind of Q logic box,

or this one?


Cuz the latter are pretty good.

 

I agree with fcm, though the later's of you last pics suspended shown are better sealing, even cutting the carpet away on those shown first still suck *******.

Yes, any air escaping around the sub even if it's a little puff of air can completely change the sound quality of the sub vs. the box and the air being used. Even a small amount of air escaping around the surround of the sub on a ported box can seriosly expletive the sound and performance of the sub.

 

I have not seen the box in the second pix, so I don't know, my opinion of Q logic boxes is based on the year we carried them at the last place I worked, band pass boxes that blew apart, sealed boxes that leaked like a sieve and blew apart, in general poorly constructed boxes, I stopped using them for anything but low powered systems, [200W or less] and even then I beefed them up with bracing silicone and fiberglass resin. 94

 

If air gets out on a SEALED box it is a bad thing

 

Well yea, if air is "getting out", it woilden't be a "sealed" box, would it?

The problems you run into are...

Air behind the cone can "react" with air in front of the cone, or more accurately, sound waves off the back of the cone interact with the sound waves off the front of the cone, because they are 180 degrees out of phase with each other they cancel each other out and you end up with a net loss of output, [SPL].

If air is leaking out of the box, there is less control on the cone, and cone will tent to "flop" around and move past it's xmax, not a good thing.

It means the sub can not handle it's rated continuous power handling

It will also raise the F3 point, [sub can't go as "low" as it could].

Also keep in mind the volume of the box is also critical to the subs performance, as is the amp and it's RMS watts into subs impedance. 94